The present invention relates to a method of manufacturing a hollow shaft having a flange at one end thereof.
A hollow shaft to which the present invention relates is often used as an output shaft in a planetary gearing device of a speed change gear box in a motor vehicle. Such kind of hollow shaft is usually manufactured by engaging a flange member with a hollow shaft member through plastic working treatment by virtue of caulking combination.
Japanese Unexamined Patent Publication No. 58-100926 has disclosed a shaft manufacturing method in which a ring-like member is integrally formed at one end of a hot low shaft through plastic working treatment. In detail, an end portion of a cylindrical work piece engaged with a ring-like member is bent backwardly, so that the cylindrical work piece and the ring-like member may be firmly fixed together by virtue of caulking combination.
Further, Japanese Unexamined Patent Publication No. 10-156450 has disclosed another shaft manufacturing method in which a ring-like member is engaged at one end of a hollow work piece, an outer periphery portion of the hollow work piece protruding beyond the ring-like member is bent towards the ring-like member, so that the ring-like member and the hollow work piece may be firmly fixed together by virtue of caulking combination.
However, each of the above manufacturing methods requires that part of a hollow work piece protruding beyond a ring-like member (engaged with the hollow work piece) is subjected to a plastic working treatment so that the ring-like member may be pressed in the axial direction so as to be fixed in the hollow work piece. Although each of these methods is proved to be effective in securing a ring-like member (having a predetermined thickness in its axial direction) on to a hollow shaft with a predetermined strength, none of them has been provided to be effective in firmly securing a plate-like member onto a hollow shaft by virtue of caulking combination.